Moisture indicator for webs



5 Sheets-Sheet 1 m T A INVENTOR.

June 26, 1951 J. 5. SENEY MOISTURE INDICATOR FOR WEBS Original FiledOct. 8, 1946 June 26, 1951 J. 5. SENEY 2,558,392

MOISTURE INDICATOR FOR WEBS Original Filed Opt. 8, 1946 5 Sheets-Sheet 2.53 1 Z5 5 I .45 I E59 *60 PL 1 A r INVENTOR.

Jbhn .5. .Senqy BY A TTORNEY June 26, 1951 5, SENEY 2,558,392

MOISTURE INDICATOR FOR WEBS Original Filed Oct. 8, 1946 5 Sheets-Sheet 5IN V EN TOR.

JOlUi 5.562765 A T TORNEY June 26, 1951 s, SENEY 2,558,392

MOISTURE INDICATOR FOR IEBS Original Filed Oct. 8, 1946 5 Sheets-Sheet 4IN VEN TOR.

John 5.56166] BY ATTORNEY June 26, 1951 J. 5. SENEY MOISTURE INDICATORFOR WEBS 5 Sheets-Sheet 5 Original Filed Oct. 8, 1946 I INVENTOR. John5. Sang Y 1 dDA'Z mW AT T ORNEY Patented June 26, 1951 MOISTUREINDICATOR FOR WEBS John S. Seney, Richmond, Va., assignor to E. I. duPont de Nemours & Company, Wilmington, I Del., a corporation of DelawareOriginal application October 8 1946, Serial No. 701,954,'now Patent No.2,508,045, dated May 16, 1950. Divided and this application May 14,1949, Serial No. 93,321

3 Claims. 1

This invention relates to moisture indicators for traveling webs, andmore particularly to a device for measuring and integrating the totalmoisture content of each run over a predetermined period of time, and,in addition, for indicating the instantaneous moisture content at alltimes during the run. The invention is applicommercial slashers or thelike.

Another object is to provide a timer for usewith an electrical measuringdevice of the above type which is responsive to the electricalresistance of the web.

Another object is to provide a timer for use with a device of the abovetype which measures both the instantaneous resistance and the averageresistance over a period of time.

Another object is to provide a timer for use with a device of the abovetype which does not require special operating skill for its use.

Various other objects and advantages will be apparent as the nature ofthe invention is more fully disclosed.

In accordance with the present invention, a continuous measurement ismade 'of the electrical resistance of a portion of the web, such as thethread sheet of the slasher, which in turn is a function of its moisturecontent. For this purpose, the entire thread sheet of the slasher ispassed between a pair of stainless steel rolls located behind the lastdrier can. Therolls are connected in an electrical circuit with acondenser which is successively charged and discharged at a ratedependentupon the electrical resistance of the portion of the threadsheet extending between the rolls. An electrical counter means isprovided for counting the number of times the condenser is charged anddischarged during a predetermined period of time, this numberrepresenting a measure of the total moisture content. Means is alsoprovided for measuring the charging time of the condenser and indicatingthe same on a suitable scale which is graduated directly to readmoisture'content. Means may also be provided to actuate a signalling orcontrol device when the variation in moisture content exceedspredetermined limits.

, Although the novel features which are believed to be characteristic ofthis invention are pointed out more particularly in the claims appendedhereto, the nature of the invention will be better understood byreferring to the following description, taken in connection with theaccompanying drawings in which a specific embodiment thereof has beenset forth for purposes of illustration.

In the drawings:

Figure 1 is a front elevation of the moisture indicating instrument;

Figure 2 is an end elevation taken from the right hand side of Figure 1;

Figure 3 is an end elevation taken from the left hand side of Figure l;

Figure 4 is a section taken on the line 4-4 of Figure 2;

Figure 5 is a top plan view of the instrument; Figure 6 is a verticalsectiontaken on the line 6-6 of Figure 5; and

Figure '7 is a schematic diagram showing the electrical circuitsinvolved.

Referring first to Figures 1 to 6, the electrical timing instrument isshown as comprising an electric clock motor 10 driving a gear II whichis connected to a gear I2 forming one side of a diiferential. The gearsII and I2 are journalled for free rotation on a shaft 13. A gear l4journalled on the shaft l3 constitutes the other side of thedifferential and carries a drum I5 which is engaged by a brake [6 toprevent the drum l5 and gear H from turning. The differential cagecomprises a pinion l1 meshing with the gears l2 and I4 and carried on ashaft H! which is pinned to the shaft I3 to drive the same. The shaft [3drives a shaft 20 through a gear train 2|. I The shaft 20 carries adriving arm 22 and is provided with a spring 23 which resets the drivingarm 22 to zero position when the brake I6 is released.

With the brake l6 engaging the drum I! to lock the gear ll againstturning, the motor "I drives gear I2 and pinion H which rotates'aboutthe stationary gear 14 and drives the shaft H which, in turn, throughthe gear train 2|, drives the arm 22. The arm 22 continues to be drivenwhile the brake I6 is in locked position. When the brake I6 is released,however,the gear I4 is 'free to rotate as an idler gear and is driven bythe pinion ll without causing the latter to ro-- tate about theperiphery thereof. Hence, the shaft [3 is no longer drivenby the pinionH but is free to rotate, and may be rotated in the opposite direction bythe spring 23 to return the arm 22 to its zero position.

The brake I6, as shown in Figure 4, comprises a brake shoe 25 whichengages the drum I and is mounted upon an arm 26, pivoted on a pin 21.The arm 26 carries a bracket 28 to which an armature 29 is attached. Thearmature 29 is associated with the magnetic circuit of an electromagnet30 having a winding 3I which is arranged to attract the armature 29 andset the brake shoe against the drum I5 when the electromagnet isenergized.

The arm 26 also carries a finger 33 which engages the operating lever 34of a microswitch 35 in a manner to close the switch contact when theelectromagnet 30 is deenergized and the finger 33 is retracted to theposition shown, but to open the microswitch contact when theelectromagnet 30 is energized to set the brake shoe 25 against the drumI5 and to causethe arm 26 to pivot about the pin 21 so that the finger33 presses upwardly against the switch lever 34. The purpose of theswitch 35 will be explained in connection with Figure 7.

A contact arm (Figures 1 and 6) carrying a pair of contacts H isjournalled about the shaft 20 and is normally urged to zero position bya spring 42. A member 43 acts as a stop to limit the opening of thecontacts 4|. A lip 44 carried by the driving arm 22 engages one side ofthe contacts H, which closes the contacts 4I when the driving arm 22reaches a position to register with the contact arm 40. The contact arm40 carries a pointer 45 registering with a dial 46 which may be markedto read directly in percentage moisture content. The arm 40 also carriesa bracket 48 to which a brake member 47 is attached. The brake member 41engages an arcuate brake shoe 50 which is pivoted at 5| at one end and,at its other end, carries an armature 52 (Figures 1 and 2) which forms apart of the magnetic circuit of an electromagnet 53 having a winding 54.When energized, the electromagnet 53 attracts the armature 52 and raisesthe brake shoe 50 from the brake member 41, thereby allowing the spring42 to turn the arm 40 to the left until it engages the driving arm 22 orreaches its zero position. With the electromagnet 53 deenergized, thebrake shoe 54 rests upon the brake member 41 and exerts sufilcientfriction to prevent the arm 40 from being returned due to the action ofthe spring 42. The drag exerted by the brake shoe 50 is insufficient,however, to prevent the arm 40 from being driven in a clockwisedirection, as seen in Figure 1, by the driving arm 22. The arm 40 isthus retained in its driven position by the brake shoe 50 when thedriving arm 22 is reset to zero.

The arm 40 also carries a cam (Figures 1 and 2) which is set to actuatea double throw switch 6| having an arm 52 and contacts 83 and 64 whichare selectively closed in accordance with the position of the arm 62.The contacts 63 and 54 are actuated in accordance with the position ofthe contact arm 40 and are arranged to-be selectively closed when theposition of the arm 40 represents an excessive moisture variation.

Referring to Figure '7, the electrical system is shown as supplied froma power source including lines and BI and controlled by a switch 82. Thelines 80 and Ill are connected to the primary 83 of a transformer 84having a pair of secondary sections 85 and 86. One end of the secondary85 is connected by a line 81 to the cathode 88 of a space dischargerectifier tube 89, the anode 90 of which is connected by a line 9| to acondenser 92, thence by a line 93 to the common point of th'esecondarysections 35 and 86. A potentiometer 94 is connected across the condenser92. The tube 89 constitutes a rectifier which is arranged to cause aunidirectional current flow through the potentiometer 94 to develop apotential drop thereacross. The condenser 92 serves to smooth out thevoltage variations and produce a substantially uniform potential dropacross the potentiometer.

The secondary section 86 is connected to a condenser 98 and thence tothe anode 99 of a space discharge tube I00, which may be of the Pliotrontype, and is provided with a grid IM and a cathode I02. A condenser I 03is connected between the grid IM and cathode 102. The cathode side ofthe condenser I03 is connected by a line I04 to the return line 93. Thegrid side of the condenser I03 is connected by a line I05 to a slasherroller I06. The variable tap I01 of the -potentiometer 94 is connectedby a line I00 to a' contact I09 of a relay IIO having an energizing coilIII. An arm I I2 which cooperates with the contact I09 is connected by alead II3 to one side of a jack II4, the other side of which is connectedby a line II5 to a second slasher roll II. The slasher rolls I06 and H6are positioned beyond the last drier can of the slasher and are soarranged that the entire thread sheet is passed between the two rolls sothat a circuit is established between the rolls due to the conductivityof the intervening portion of the thread sheet.

A relay coil I20 is connected across the condenser 98. The coil I20actuates an armature I2I which, in turn, actuates an arm I 22 which isnormally closed against a contact I23. The arm I22 and contact I23 areconnected by lines I24 and I 25 respectively across the condenser I03.

In the operation of the circuit thus far described, a potentialisapplied from the tap I01 of the potentiometer 94, through contact I09and arm II2 (when closed) and through jack II4 to the roll IIB, thencethrough the slasher thread I26 to the roll I06 and through line I05 tocondenser I 03. The other side of condenser I03 is connected to thepotentiometer 94 by line I04, thus completing the condenser-chargingcircuit. Current flowing from the secondary 86, through tube I00 and thecoil I20, holds the contact I23 open. The condenser I 03 continuouslycharges in a direction to make the grid IOI of the tube I 00 negative.When the charge on the condenser I03 reaches a value such that the gridI 0| is biased to its cut-off point, the tube I00 becomesnon-conductive, thereby interrupting the current flow through the relaywinding I20 and releasing the armature IN. This closes the contact I23and short-circuits the condenser I03 to drain the negative chargetherefrom and allow the grid IM to return to its normal potential. Thetube I00 thereupon again becomes conducting and the cycle is repeated.The condenser I03 repeatedly charges to the cut-off voltage and isdischarged by the de-energization of the relay coil I20 in a cycle, thefrequency of which is dependent upon the rate of charge of the condenserI03.

It will be noted that the rate at which the condenser I03 charges isdependent upon the resistance of the thread sheet between the rolls I06and H6 which, as previously pointed out, is a function of the moisturecontent of the thread. This cycle may take, for example, ten secondswith a normal moisture content.

It will be evident from the above that, by counting the number ofcharges and discharges over a predetermined period of time, anintegrated aseasaa value of the moisture content over that interval maybe obtained. Also, by timing the rate of charge or the condenser I03, aninstantaneous value of the moisture content will be obtained. This isaccomplished by the remainder of the circult of Figure 7 to bedescribed.

A step-by-step relay I is provided with a ratchet I3I actuated by anarmature I32 and a relay coil I33 which is shunted by a condenser I34.The ratchet mechanism drives a rotor I35 having a plurality of bossesI36 thereon which are adapted to actuate a switch arm I31. In oneposition, the switch arm I31 closes contacts I38 and I38, and in theother position contacts contact i40. The ratchet mechanism I3I is sodesigned that two operations of the ratchet are required to shift therotor I35 from the position in which one boss I36 actuates the arm I31to a position in which the arm I31 has been released and again actuatedby the next boss I36. Such a step-by-step relay may be of any standardconstruction.

A counter I is provided with an actuating coil I46 which actuates thecounter register I41 and with a reset button I48 which is normally heldoutward by a spring I48, but is pushed inwardly against the force of thespring I48 to reset the counter. The reset button I48 actuates an armI50 which normally closes a contact I5I but auto matically opens thecontact I5I when the knob I48 is pressed inwardly for resetting thecounter.

A timer I is provided, which is similar to the timer shown in Figures 1to 6, with the cam 60, brake shoe 50, and switch 35 omitted. The timerI55 comprises the usual clock motor operated by a coil I56 and a clutchcoil I51 which is similar to the coil 3I of the timer illustrated inFigures 1 to 6, and controls the operation of the driving arm. The timercontact I58, carried by a contact arm, is normally closed but isarranged to be opened when the driving arm of the timer engages thecontact arm. The contact arm in this case is pre-set for the time it isdesired for the timer to operate.

A line I is connected by a line I66 to the supply line 80. This line isconnected through a high speed switch I61 to the relay coil III, thereturn connection being grounded. The high speed switch I61 constitutesa centrifugal switch which is arranged to be closed when the slasher isoperating at normal speed but to be opened when the slasher has beenstopped. Hence, the relay coil III is energized during such times as theslasher may be running. Energization of the coil III closes the contactI08, as previously described, to supply current to the slasher rolls I06and I I6. It also closes arm I68 against contact I68. Actuation of theswitch I81 also closes the circuit to clock coil I56 through a line I10.Hence, the clock motor I56 likewise operates only during the time thatthe slasher is running. Test jack I is connected across the switch I61to permit the system to be checked when the slasher is stopped and theswitch I61 is open.

The armature I2I of the relay coil I20 actuates arm I12 to close acontact I13. The contact I13 is connected by a line I14 to a variableresistor I15, thence by a line I16 to one side of the relay coil I33.The other side of the relay coil I33 is connected by line I11 to thesupply line I65. Hence, the relay coil I03 is energized once each timethe coil I20 is operated and the contact I38 is closed at every otheroperation of the coil I20.

The arm I31 0! the ratchet relay is connected by a line 200 to thesupply line J88. The contact I38 is connected by a line 985 to thecounter coil M6, thence by a line I82 to the normally closed contact I580! the timer H5. The arm I58 0! the timer I56 is connected by a line I83to the normally closed contact I5I oi the counter, the arm I50 01 whichis grounded by a line I84. Hence, closing of the contact I 38 completesthe circuit through the counter coil I46 provided the contacts I58 andI5I are closed and causes the counter coil I46 to register every otheractuation oi the coil I20.

When the timer I55 has operated a sufllcient period of time for itsdriver arm to engage the contact arm and open the contact I58, thecounter coil I46 is de-energized and no further actuations of the coilI20 are registered on the counter register 141.: The register thenindicates hall the total number of actuations oi. the coil I20, which inturn represents halt the total number of charges applied to thecondenser I03 during the timed period. By referring to a suitable chart,the integrated moisture content for the period may be noted. This periodmay, for example, represent the normal running time of a slasher beam,for example 2 hours.

After the reading of the counter I45 has been noted or when a newslasher beam is placed on the machine, the device may be reset bypushing the reset button I48, thereby resetting the counter register I41and' opening the contact I5I. Opening the contact I5I breaks the circuitthrough the clutch coil I51 of the timer and causes the timer to bereset to zero. When the reset button I48 is released, contact I5I isagain closed and the counter is ready for another cycle of operation.

For timing the interval between every other actuation of the coil I20, asecond timer I is employed which is of the type shown in Figures 1 to 6,and previously described. This timer comprises the clock motor coil I0which is connected by a line I8I to switch I82 and by line I83 to thearm I68 of the relay H0, and thence through contact I68 of the relay II0 to ground. The other end of the clock coil I0 is connected by lineI00 to a normally closed contact I85 01 a relay I83 having an actuatingcoil I81. The contact I engages an arm I88 which is connected by a lineI88 to the supply line I65. Hence, the clock coil is energized throughthe back contact I85 whenever the relay I86 is de-energized and therelay H0 is energized, which is the normal operating condition. Thecontact I85 is also connected by a line 200 and line "I to the clutchcoil 3i of the timer I80 and through lines 203 and 202 to the contactI40 of the ratchet relay I80. It will be noted that the clutch coil 3iand the clock coil I0 are normally supplied through the contact I85 whenthe latter is closed. However, when the contact I85 is opened and thecontact I40 is closed, the above coils are supplied through the contactI40.

Contact I38 is connected by a lead 203 to an arm 204 of the relay I86which normally en gages contact 205. The contact 205 is connected by aline 206 to the brake release coil 54 of the timer I80.

Contacts 63 and 64 of the timer I88 are connected by lines 201 and 208to control lines 20 and 2 I0 respectively and to a pair of signal lights2 and 2I2 respectively. The signal lights 2H and 2I2 are shown asconnected through a variable resistor 2I3 and line 2 to the supply lineI65.

greases The microswitch 35 is provided with a contact 229 which isconnected by a line 22I to a contact 222 which engages the arm I98 whenthe relay I 96 is actuated. The coil I97 of therelay I9: is connected bya line 223 to the contacts EI an. thence by a lead 224 to the arm 22b ofthe microswitch.

The operation of the timer I9il is as follows: The clock motor I of thetimer 59b is energized whenever the relay coil III is energized andcontact I40 is closed, that is whenever the slasher is running. Hence,the clock operates to advance the driving arm 22 (Figure 1) whenever theslasher is running and contact M6 is closed and the clutch coil 3!! isenergized.

with the relay I9? de-energized, the clock motor Ill and the clutch coil39 are supplied through the contact I95 as above described. When theratchet relay I is advanced to close the contact I49, the clock motorcoil I9 and clutch coil M are energized through the contact Mtregardless of whether or not the contact I95 has meanwhile opened.

When the ratchet relay has advanced one step to again open the contact Iand close the contact I33, the brake release coil 54 is energizedthrough the contact I38 and the contact 205 of the relay I96, therebyelevating the brake shoe 30 and allowing the contact arm 40 to bereturned in a counterclockwise direction by the action of the spring 42until it engages the driving arm 22, thereby momentarily closing thecontact 48. Closing the contact 4I energizes the relay I96, therebyopening the contact 205 and de-energizing the coil 54 to allow the brakeshoe 5'! to again engage the brake member 41 and hold the arm 40 in itsthen position. Actuation of the relay also opens the contact I95 andcloses the contact 222. Opening the contact I95 interrupts the circuitthrough the clock motor Ill and through the clutch coil 3|, therebyreleasing the clutch coil and allowing the arm 22 of the timer I90 to bereturned to zero position by the spring 23. Movement of the arm 22 awayfrom the contact arm 40 allows the contacts 4| to again open. At thesame time, release of the coil 3I closes the microswitch 35 which actsas holding contact on the relay I96 to hold the same in actuatedposition. It will be noted that the pointer 45 is now held at a positionwhich corresponds to the maximum clockwise position of the driving arm22 before the timer was reset.

At the next step of the ratchet relay I30, contact I40 is closed therebyagain energizing the clock motor I0 and the clutch coil 3I.Energization' of the clutch coil 3I breaks the contact of themicroswitch 35 and releases the relay I96.

It will be noted that if the succeeding cycle being timed is longer thanthe previous cycle, the contact M will close due to the driving arm 22engaging the contact arm 40 before the contact I38 is closed by theratchet relay. As soon as the contacts 4| close the relay I96 operates,breaking the circuit to the brake release coil 54. Hence, the brake shoeis not elevated and the indicator arm 49 retains its new position whenthe driving arm 22 is reset. If, however, the subsequent time period isshorter, the contact I38 closes first, thereby releasing the indicatorarm 49 and allowing the same to drop against the driver arm 22, as abovedescribed. Hence, the indicator arm 40 always indicates the length ofthe last cycle or the time required for the next to the last charge ofthe condenser I03, and the pointer 45 gives an indication of theinstantaneous value of the moisture content for this cycle.

The cam and the contacts 63 and 66 may be used to actuate a controlsystem when this moisture content exceeds or is reduced below apredetermined value, or the pilot lights 2 and 262 may be selectivelyactuated to indicate that the moisture content has risen too high orfallen too low. Thereupon, suitable control may be effected by theoperator.

A specific embodiment of the invention has been shown for purposes ofillustration only, and it is to be understood that the invention may beapplied to various uses and that changes and adaptations may be madetherein as will be readily apparent to a person skilled in the art. Theinvention has been described specifically as applied to a slasher. Theweb Iii; may, however, constitute any flexible non-conducting web, themoisture content of which is to be measured, such as a cellophane web orother cellulosic or fibrous material.

Since it is obvious that many changes and modifications can be made inthe above-described details without departing from the nature and spiritof the invention, it is to be understood that the invention is not to belimited thereto except as set forth in the appended claims.

I claim:

1. An impulse timer comprising a driving arm, timed drive means for saidarm, connections including a clutch to connect said arm to be driven bysaid drive means, spring means to reset said arm when said clutch isreleased, a contact arm driven by said driving arm and having a contactactuated by contact with said driving arm, a brake to hold said contactarm in position, spring means to reset said last arm when said brake isreleased, and electromagnetic means actuating said clutch and saidbrake.

2. An impulse timer comprising a driving arm, timed drive means for saidarm, connections including a clutch to connect said arm to be driven bysaid drive means, spring means to reset said arm when said clutch isreleased, a contact arm driven by said driving arm and having a contactactuated by contact with said driving arm, a brake to hold said contactarm in position, spring means to reset said last arm when said brake isreleased, electromagnetic means actuating said clutch and said brake,cam means on said contact arm, and contacts selectively closed by saidcam means in difierent positions thereof.

3. An impulse timer comprising a driving arm, timed drive means for saidarm, connections including a clutch to connect said arm to be driven bysaid drive means, spring means to reset said arm when said clutch isreleased, a contact arm driven by said driving arm and having a contactactuated by contact with said driving arm, a brake to hold said contactarm in position,

spring means to reset said last arm when said REFERENCES CITED Thefollowing references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Andrews Sept. 20, 1938 Number

